problem in adding values in jtable column

**blustar angel** · 08-27-2012, 03:58 PM

hi,
i need solution urgently for this problem.
i have a table cartTBL that has 2 columns name and price,i need to add all the values in the price column and display it in a label .the amount should be changed as an item is added or removed.
i tried many codes ,nothing seems to work.

**Zyril** · 08-27-2012, 04:16 PM

First of all, post some of your code. We need to know more about what you've tried (and not) before we can help you.
Secondly, we need to know what your code looks like so we can tell you right away if you are doing it wrong or not.

When you say "display it in a label", what do you mean? Do you want to display it in a JTable cell OR a JLabel somewhere else?

Are you using a table model?

If you post code, use the [CODE]-tags.

**Norm** · 08-27-2012, 04:26 PM

Is this the same problem: help with jtable | DaniWeb

**blustar angel** · 08-27-2012, 04:42 PM

DefaultTableModel tm = (DefaultTableModel)cartTBL.getModel();
int total=0;
int i;
int row=CARTtbl.getRowCount();
for ( i=0; i<row ; i++){
total = total+(Integer) CARTtbl.getValueAt(i,1);
}
LBL.setText( ""+subtotal);
this is the coding

**Norm** · 08-27-2012, 04:56 PM

Can you explain what the problem is? What does the code do or not do? Are there any error messages? If so, please post them.

Please wrap posted code in code tags:
http://www.java-forums.org/misc.php?do=bbcode#code

**blustar angel** · 08-27-2012, 05:16 PM

Java Code:

Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Integer
	at HOMEPAGE.totalActionPerformed(HOMEPAGE.java:6691)
	at HOMEPAGE.access$2100(HOMEPAGE.java:15)
	at HOMEPAGE$23.actionPerformed(HOMEPAGE.java:625)
	at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
	at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
	at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
	at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
	at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
	at java.awt.Component.processMouseEvent(Component.java:6505)
	at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
	at java.awt.Component.processEvent(Component.java:6270)
	at java.awt.Container.processEvent(Container.java:2229)
	at java.awt.Component.dispatchEventImpl(Component.java:4861)
	at java.awt.Container.dispatchEventImpl(Container.java:2287)
	at java.awt.Component.dispatchEvent(Component.java:4687)
	at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
	at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
	at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
	at java.awt.Container.dispatchEventImpl(Container.java:2273)
	at java.awt.Window.dispatchEventImpl(Window.java:2719)
	at java.awt.Component.dispatchEvent(Component.java:4687)
	at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:703)
	at java.awt.EventQueue.access$000(EventQueue.java:102)
	at java.awt.EventQueue$3.run(EventQueue.java:662)
	at java.awt.EventQueue$3.run(EventQueue.java:660)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
	at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
	at java.awt.EventQueue$4.run(EventQueue.java:676)
	at java.awt.EventQueue$4.run(EventQueue.java:674)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:673)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:244)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:163)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:147)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:139)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:97)

this is the error i am facing

**Norm** · 08-27-2012, 05:24 PM

java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Integer

It looks like the getValueAt() method returns a String object not an Integer object.
To see what is returned, add a println() statement that prints out what is returned by getValueAt().
If the String is all digits you could use the Integer class's parseInt() method to convert the String to an int.

**blustar angel** · 08-27-2012, 07:15 PM

can you tell me where i should this statement. i am realy confused.

**Norm** · 08-27-2012, 07:44 PM

Inside the loop where you call the getValueAt() method.

Java Code:

     for ( i=0; i<row ; i++){
         System.out.println("i=" + i + " gVA=" +  CARTtbl.getValueAt(i,1));
         total = total+(Integer)  CARTtbl.getValueAt(i,1);
     }

The error message you posted shows that the program you are working on has over 6691 lines. Its hard to imagine how you got such a large program and don't know how to debug problems. Can you explain how you got this code?

**blustar angel** · 08-27-2012, 09:44 PM

i am doing a project in my school.
even i am amazed that i have so much of line.
it returns an int value.now what should i do.how can i display it in a label

**Norm** · 08-27-2012, 10:12 PM

Please post what is printed out by the println statement that you added.

**blustar angel** · 08-27-2012, 10:33 PM

Java Code:

i=0 gVA= 178
Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Integer
	at HOMEPAGE.totalActionPerformed(HOMEPAGE.java:6692)
	at HOMEPAGE.access$2100(HOMEPAGE.java:15)
	at HOMEPAGE$23.actionPerformed(HOMEPAGE.java:625)
	at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
	at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
	at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
	at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
	at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
	at java.awt.Component.processMouseEvent(Component.java:6505)
	at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
	at java.awt.Component.processEvent(Component.java:6270)
	at java.awt.Container.processEvent(Container.java:2229)
	at java.awt.Component.dispatchEventImpl(Component.java:4861)
	at java.awt.Container.dispatchEventImpl(Container.java:2287)
	at java.awt.Component.dispatchEvent(Component.java:4687)
	at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
	at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
	at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
	at java.awt.Container.dispatchEventImpl(Container.java:2273)
	at java.awt.Window.dispatchEventImpl(Window.java:2719)
	at java.awt.Component.dispatchEvent(Component.java:4687)
	at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:703)
	at java.awt.EventQueue.access$000(EventQueue.java:102)
	at java.awt.EventQueue$3.run(EventQueue.java:662)
	at java.awt.EventQueue$3.run(EventQueue.java:660)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
	at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
	at java.awt.EventQueue$4.run(EventQueue.java:676)
	at java.awt.EventQueue$4.run(EventQueue.java:674)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:673)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:244)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:163)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:147)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:139)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:97)

it prints out the value as well as error also comes.
:(

**Norm** · 08-27-2012, 10:44 PM

i=0 gVA= 178

Is that space between the = and the 178 in the object or was it in the println?

What try of object is returned by the getValueAt() method? Change the println to this to see:

Java Code:

 System.out.println("i=" + i + " gVA="+  CARTtbl.getValueAt(i,1).getClass());  // show class

When you find out what type the object is you will know how to get a numeric value from it.

**blustar angel** · 08-27-2012, 11:13 PM

i=0 gVA=178

this is the output plus the error which i got previously.

**blustar angel** · 08-27-2012, 11:17 PM

are u sure wether my coding is correct.i am a newbie so it takes time.

**Norm** · 08-28-2012, 01:13 AM

i am a newbie so it takes time.

How can that be with a program with over 6691 lines????

What was printed when you Changed the println to this:

Java Code:

 System.out.println("i=" + i + " gVA="+  CARTtbl.getValueAt(i,1).getClass());  // show class

**blustar angel** · 08-28-2012, 10:50 AM

[QUOTE][i=0 gVA=class java.lang.String/QUOTE]
is the output.

**Norm** · 08-28-2012, 01:28 PM

If the object is a String that contains numeric digits, you can use the Integer class's parse method to convert it to an int that can be added to the total.